Circuit Description
The Passlock™ System is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate. The Passlock™ controller reads the coded Passlock™ data signal. The data consists of a voltage generated by a voltage divider network created between the Passlock™ assembly and the Passlock™ controller. If the data is correct , indicating rotation of the lock cylinder with the proper mechanically cut key, then the Passlock™ controller sends a password to the powertrain controller via serial data to indicate that engine starting should be allowed. The Passlock™ controller also interfaces with the driver displays subsystem to indicate, via the security indicator, the Passlock™ subsystems status and acute subsystem failures.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2955 Security System Sensor Data Circuit
DTC Symptom | DTC Symptom Descriptor |
|---|---|
00 | No Additional Information |
Conditions for Setting the DTC
| • | The ignition switch is ON. |
| • | The body control module (BCM) signal input is less than 0.4 volts for 1 second after turning the ignition switch to the CRANK position. |
Action Taken When the DTC Sets
| • | The vehicle will not start if the fault occurs before you start the vehicle. The security indicator will flash for 10 minutes then turn ON steady. |
| • | If the vehicle is running when the fault occurs, the BCM will be in the fail enable mode allowing the vehicle to start and run. The security indicator will be ON. |
Conditions for Clearing the DTC
| • | The DTC will clear once the ignition cycle has occurred without the fault recurring. |
| • | The BCM history codes will clear once 100 concurrent ignition cycles occur without the fault recurring. |
| • | The DTC can be cleared using a scan tool. |
Diagnostic Aids
| • | Use a scan tool in order to inspect the Passlock™ data voltage and the Passlock™ code. |
| • | Inspect the Passlock™ sensor harness for an intermittent or a short to ground. Refer to Testing for Intermittent Conditions and Poor Connections . |
| • | Following a repair the tamper timer needs 10 minutes in order to expire. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests for proper operation of the 5-volt reference circuit from the BCM.
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This step checks for a voltage drop through the Passlock™ resistor located in the ignition switch. Voltage in this step will vary due to unique differences in each individual Passlock™ resistor.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||
Is the 5-volt reference signal circuit voltage approximately equal to the specified value? | 5 V | Go to Step 3 | Go to Step 4 | |||||||
Important: Do not start the vehicle. Is voltage measured at the Off/Run/Crank voltage circuit? | -- | Go to Step 6 | Go to Step 5 | |||||||
4 | Inspect the 5-volt reference circuit for the following:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 6 | ||||||
5 | Inspect the Off/Run/Crank voltage circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 7 | ||||||
6 | Inspect for poor connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 8 | ||||||
7 | Inspect for poor connections at the ignition switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 9 | ||||||
8 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- | ||||||
9 | Replace the ignition switch. Refer to Ignition and Start Switch Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- | ||||||
10 | Perform the Programming Theft Deterrent System Components procedure. Is the repair complete? | -- | Go to Step 11 | -- | ||||||
11 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
